Dental matrix-retainer.



No. 785,619. PATENTED MAR. 21, 1905.

G. M. LEPFINGWELL. I DENTAL MATRIX RETAINER.

APPLICATION FILED JUNE 22, 1904.

'IIIIIII l lining-1 Witneawo Patented March 21, 1905.

CLOSSON M. LEFFINGVVELL, OF LITTLEFALLS, MINNESOTA.

I DENTAL MATRIX-RETAINER.

SPECIFICATION forming part of Letters Patent No. 785,619, dated March21, 1905.

Application filed June 22, 1904. Serial No. 213.746.

To all whmn it may concern:

Be it known that I, GLossoN M. LEFFING- WELL, a citizen of the UnitedStates, residing at the abutting means against one side of the tooth andto adjust the band-retaining means against the opposite side thereof.

The invention also resides in the particular combination and arrangementof parts and in the precise details of construction hereinafterdescribed and claimed as an embodiment of the invention.

In the drawings forming part of this specification, Figure 1 is a planview of a device constructed in accordance with the invention. Fig. 2 isa horizontal section thereof, partly in elevation. Fig. 3 is atransversesection on the line 3 3 of Fig. 2. Fig. 4is an end elevation of theswiveled head designed to abut against one side of the tooth which isencircled by the matrix-retaining band.

Like reference characters indicate corresponding parts in the severalviews.

The numeral 1 indicates a block which is formed on opposite sides withrecesses 2 2. In each of the recesses 2 2 is formed a shoulder 3. Towardthe rear end of the block the recesses 2 2 open into a large recess orcutaway portion 4. Pivoted. to the block 1 by means of pins 8 8 areclamping members 5 5, which are adapted when closed to fit into therecesses 2 2. Each ofthe clamping members 5 is formed with a shoulder 6and is provided with a pin 7. A band 9 surrounds the'block 1 andclamping members 5. When the band 9 is pushed forward against the pins7, the clam ping members 5 are held closed, and when said band is movedin the opposite direction the clamping members may be opened. Thepivot-pins 8 8 of the clamping members pro ject slightly at their endsbeyond the surface of the block 1, whereby they serve to prevent theband 9 from slipping entirely off the block when the clamping member isopened, the pins 7 serving the same function at the opposite end of theblock when the clamping members are closed.

The matrix-retaining band 10 is fitted atits ends into the recesses 2 2.When the clamping members are closed, the shoulders 6 thereon, inconjunction with the shoulders 3 of the recesses, exert a firm grippingor biting action thereupon by causing it to bend, as clearly shown inFig. 2. It will be observed that the ends of the matrix-retaining bandare disposed in the cut-away portion4of the block 1, whereby the bandmay be adjusted readily in a longitudinal direction upon the block toform a large or a small loop, according to the size of the tooth to beencircled.

Extending through the block 1 is a screwshaft 11, which is provided atits forward end with a swiveled head 12, which rests against a collar 13on the screw-shaft and is held in place by a nut 14. The swiveled head12 is formed with concave portions or semicylindrical channels 15 15,which cross each other at a right angle, as clearly shown in Fig. 4.

The end 16 of the screw-shaft 11 is squared to receive a finger-nut 17which is capable of being removed so that it will not be in the wayduring the operation of forming a matrix.

In using the device the tooth which is to be operated upon is encircledby the band 10 and the screw-shaft 11 is rotated to adjust the swiveledhead 12 against the convex surface of one side of the tooth and to drawthe matrix-retaining band against the opposite side thereof.

An important advantage of the device described is that it is adapted toclamp firmly a celluloid matrix-retaining band, aswell as a steelmatrix-retaining band. Furthermore,

any simple form of band or celluloid ribbon may be employed with it.

In former devices of a similar character it is necessary generally toemploy a steel band of peculiar construction, usually with perfo- IOOrations in its end. A celluloid band could not be used with such priordevices, as the perforated ends would not stand the strain. It ispreferable to use celluloid bands as contemplated by this invention, assuch bands are cheaper than steel bands. Furthermore, they do not retardthe hardening of the material from which the matrix is made, as is thecase frequently with steel bands.

Changes in the precise embodiment of the invention illustrated anddescribed may be made within the scope of the following claims withoutdeparting from the spirit of the invention or sacrificing any of itsadvantages.

Having thus fully described the invention, what is claimed as new is 1.A dental matrix-retainer comprising a block having pivotedclampingarms,a matrixretaining band held by the clamping-arms, ascrew-shaft extending through the block, and a head swiveled upon theend of the screwshaft and adapted to abut against the tooth encircled bythe band.

2. A dental matrix-retainer comprising a block having shoulderedrecesses in its sides,

a clamping member pivoted in each of the recesses and having a shoulderthereon, a band surrounding the block and the clamping members and-movable longitudinally thereon to hold the clamping members in closedposition, a matrix-retaining band held by the clamping members, ascrew-shaft extending through the block, and a channeled head swiveledupon the end of the shaft and adapted to abut against the convex surfaceof the tooth encircled-by the matrix-retaining band.

3. A dental matrix -retainer comprising a matrix-retaining band, a headadapted to abut against a tooth, and having channels therein crossingeach other at an angle, and means for adjusting the head against oneside of the tooth and for drawing the retaining hand against theopposite side thereof.

In testimony whereof I aflix my signature in presence of two witnesses.

CLOSSON M. LEFFINGWVELL.

Witnesses:

N. N. BERGHEIM, DON M. CAMERON.

